The phase diagram of a binary mixture of 4-n-octyloxy-
phenyl–4′-n-heptylcyclohexane carboxylate (molecule having weak polar
terminal group) and 4-nitrophenyl-4′-n-pentylbenzoate (molecule having
strong polar terminal group) has been studied using polarizing microscope and
differential scanning calorimeter. The phase diagram shows an enhancement in
smectic A phase over a wide composition range and intermediate nematic phase in
a narrow composition range. The dielectric properties of these phases are
investigated in the frequency range of 100 Hz to
1 MHz.